The present invention relates to an apparatus for accumulating elongated flexible objects, such as ropes, in storage cans. More particularly, the present invention is concerned with such an apparatus which is especially suited for use in connection with reciprocating quadratic or rectangular cans, or rotating cylindrical cans, for laying the elongated object thereinto.
There are already known various apparatuses for introducing flexible objects, such as ropes, into storage cans for the flexible objects to be stored therein. These apparatuses find a very prominent, but not exclusive, use immediately downstream of a machine which produces the elongated object, such as a twisting or interwining machine in the event that the object is a rope. While the present invention will be hereafter described and discussed as used in connection with ropes or cables, it is to be understood that the basic concept of the present invention can also be used in connection with other elongated flexible objects. Thus, when the flexible object is a rope, it is already known to arrange the storage can in which the rope is to be accumulated as immediately downstream of the rope-spinning machine as practicable. Usually, upon emerging from the rope-spinning machine, the just-produced rope is trained around a plurality of pulleys, rollers or the like, and then it is introduced in between two driven cylinders which forward the rope into a can which is positioned underneath the driven cylinders. The circumferential surfaces of the cylinders can be either smooth or corrugated. When the outer surface of at least one of the driven surfaces is corrugated, the tendency of the rope to form entanglements either in the can or on its way into the can is suppressed.
However, experience with this conventional type of apparatus for accumulating ropes in storge cans has shown that many difficulties are encountered in such apparatus, primarily as a result of the relatively high speeds at which the apparatus operates in view of the relatively high speeds at which modern rope-spinning machines produce the rope which then issues and is forwarded by the driven cylinders at such a high speed toward the apparatus for accumulating the rope in a storage can. It will be appreciated that the forwarding speed of the driven cylinders will have to correspond to the issuing speed of the rope from the rope-spinning machine, so that the full utilization of the capacity of the spinning machine calls for accumulating the rope in the storage can at such a high speed. The most important problem encountered in such an apparatus is that, at such high speeds, the accumulating rope forms convolutions and entanglements in the storage can so that it becomes very difficult to subsequently withdraw the accumulated rope from the storage can for further use. Another drawback also exists when the driven cylinders are corrugated, which results from the fact that the rotating driven cylinders generate strong air currents during their rotation, which air currents cause turbulent conditions in the respective storage can so that the contents of the latter, that is, the accumulating rope, is subjected to the action of such turbulent air conditions and air currents existing because of that, as a result of which the danger of formation of entanglements in the storage can become even more pronounced.
To reduce the likelihood of the formation of such entanglements, it has been already proposed to diminish the speed of movement of the rope or cable prior to its introduction into the storage can. So, for instance, the German published patent application DT-OS No. 23 31 114 discloses an apparatus which serves this purpose and which includes a hollow body which is arranged at an angle with respect to and against the direction of movement of the fibrous cable, the hollow body being supported for pivoting and being constructed as a body of rotation. The purpose of this apparatus is to achieve a virtually impact-free transition of the movement of the cable from a straight path to a helical path within the hollow body. A uniform retardation or braking of a cable takes place at the inner wall of the hollow body which is constructed as a rotationally symmetrical guide surface.
However, even this apparatus does not eliminate the above-mentioned problems, even though it makes them less likely to occur. This is attributable to the fact that the braking of the cable or rope to a zero speed does not occur in the hollow body but rather only in the can itself. Of course, the likelihood of the occurrence of those problems which have been previously mentioned is proportional to the remaining speed of movement of the cable longitudinally thereof; nevertheless, even under the best circumstances, the cable or rope will retain some of its speed in this arrangement so that the possibility of formation of entanglements exists even under most advantageous circumstances.
A quite successful attempt to eliminate the above-mentioned problems by reducing the speed of the longitudinal advancement of the cable to virtually zero has been disclosed in a commonly owned U.S. Patent application Ser. No. 745,674, wherein the cable or rope is being advanced longitudinally thereof through a guide tube which rotates about a vertical axis and has an upstream portion surrounding, and a downstream portion deviating from, the above-mentioned axis, the downstream portion having a discharging end which orbits the vertical axis. A braking drum of a substantially cylindrical or of a slightly downwardly conically diverging configuration surrounds the orbiting trajectory of the discharging end so that the cable emerging from the latter impinges the inner surface of the braking drum and is reduced in speed to substantially zero upon such an impingement.
As advantageous as the solution may be in all other respects, experience therewith has shown that it still leaves something to be desired in other respects. Thus, it has been discovered that, after an extended period of use of this apparatus, the interior of the guide tube may become soiled by deposits carried by the cable, such as preparation, avivage, water or similar deposits. It will be appreciated that, if a depositing layer of these and other substances were allowed to develop, the operation of the apparatus and especially the speed of advancement of the cable or rope therethrough would be considerably impaired, especially when the developing layer is sticky. Thus, this apparatus is capable of operating at optimum parameters only if it undergoes frequent cleaning operations.
The problem of formation of the depositing layer is most pronounced in the rotating upright part of the guide tube, particularly as a result of the fact that the centrifugal forces acting in this rotating upright portion will force the above-mentioned substances in the radially outward direction where they will becone firmly attached.
Then, it is possible to dislodge these deposits only by resorting to rather cumbersome cleaning operations. The performance of the cleaning operations, of course, calls for an interruption of the operation of the apparatus and, hence, also of the rope-spinning machine, which substantially detracts from the optimum utilization of these devices.
Another drawback of this apparatus is that the guide tube which is rigid with a rotary body is driven from a motor by a belt drive, the motor as well as the belt drive being arranged upwardly of the braking drum. This type of a drive, which is to be operated at the required high advancement speeds of the ropes amounting to 3,000 to 6,000 meters per minute, has the disadvantage that it may be initially or may become dynamically imbalanced, the latter by deposition of fiber ends and slubs at the various components of the drive. It will be appreciated that the dynamic imbalance will result in an increased wear of the various components of the drive.
Furthermore, it has been established that the cylindrical or even the conical configuration of the inner surface of the braking drum does not present an optimum solution. Whatever the reasons therefor, it has been found that the turns of the cable which fall into the storage can sometimes overlap each other on their way into the storage can. As a result of this, there are obtained convolutions and entanglements which then create problems when the cable or rope is to be withdrawn from the storage can.